Safety device



May 29, 1962 E, B, NOLT 3,036,543

SAFETY DEVICE Filed Feb. 24, 1960 2 Sheets-Sheet 1 mvg/vr@ inw/N NoLT am 6.9M

55 ATTORNEY E. B. N OLT SAFETY DEVICE May 29, 1962 2 Sheets-Sheet 2 Filed Feb. 24, 1960 INVENTO? 50W/N /Va/.T B 9% cw (im j] ATrOR/VEY United States Patent Gliice 3,@36,543 Patented May 29, 1962 3,036,543 SAFETY DEVICE Edwin B. Nolt, New Holland, Pa., assigner to Sperry Rand Corporation, New Holland, Pa., a corporation of Delaware Filed Feb. 24, 196i), Ser. No. 10,646 1 Claim. (Cl. 11S-41) This invention relates generally to outdrive and outboard motor boats having propeller structures adapted to swing rearwardly when an obstruction is encountered. More specifically the invention relates to a safety device for such boats.

Outdrive and outboard motor boats are commonly provided with a pivotally mounted propeller structure which extends downwardly into the water. The propeller structure is adapted to swing rearwardly and upwardly if it hits an obstruction, such as a sand bar, floating board or the like. Such rearward swinging movement upon engaging an obstruction is to prevent or at least limit damage to the propeller structure.

Normally, when a swing back occurs, the propeller continues to rotate. When the obstruction has `been passed, the pivoted structure swings back to normal position. Such a swing back results from the driving force of the propeller and the force of gravity on the structure. The swing back from the force of the propeller is very hard, particularly in outdrive motor boats where there may be `a 300 Hl. motor, for example, driving the propeller. Now, even outboard motor boats often have power in the range of 8O to 100 I-LP. The swing back produced by gravity is particularly hard in an outboard motor boat because the whole motor mass overhangs the rear of the transom.

The swing back resulting from a gravity fall can be compensated for by providing shook absorbers, dampening mechanisms or other means to cushion the return. However, the thrust imparted by the propeller on a return stroke is not so readily absorbable. Frequently the structure swings back with such a force that it is capable of substantially damaging the motor drive mechanism and the rear of the boat. Likewise, the return action is sufficient to shake the boat with such a jolt that the boat operator may be thrown off balance and fall. Still further, if the propeller clears the water when it swings back, it will race freely since it is not subjected to the resistance of the water. Such racing tends to burn out the motor. Subsequently when the structure returns to the water, the propeller is subjected to a shock load which is injurious.

Frequently, when an obstruction is hit, like a floating board, the propeller structure swing back is only momentary. Usually, the structure swings back and returns before the boat operator can act and manually cut the motor. Thus, a dangerous quick stop and go action is produced.

A primary object of this invention is to provide, in an outdrive or outboard motor boat of the character described, means for automatically protecting the boat and the motor from damage when the propeller structure swings back from its normal position on hitting an obstruction.

Another object of this invention is to provide, in an outdrive or outboard motor of the character described, means for automatically reducing or cutting the power output of the motor if the propeller structure swings from its normal operating position.

Another objec-t of this invention is to provide, in an outdrive or outboard motor of the character described, means for throttling down or completely cutting the power output of the motor responsive to rearward `swinging action of the propeller structure.

A further object of this invention is to provide, a structure wherein the power output of the motor is quickly reduced during the first portion of the rearward swinging action of the propeller structure, the reduced output of the motor being retained even after the motor returns to its normal position, whereby the boat operator has control over the resumption of power.

A still further object of this invention is to provide a safety arrangement which can be readily adapted to existing outdrive and outboard motor boats.

Other objects of this invention will be apparent hereinafter from the specification and from the recital in the appended claim.

In the drawings:

FIG. l is a part side elevation part section of the rear end of an outdrive motor boat having incorporated therein a safety device constructed according to this invention. rfhe propeller structure of the boat is shown in its normal operating position;

FIG. 2 is a fragmentary side elevation similar to FIG. 1 and showing the propeller structure in a swung back position, such as it assumes after hitting an obstruction;

FIGS. 3 and 4 are diagrammatic views corresponding to FlGS. l and 2, respectively, and illustrating the actuation of the safety device;

FIG. 5 is a diagrammatic view, on an enlarged scale, showing a safety device construction `according to another embodiment of this invention; and

FIG. 6 is a fragmentary part side elevation, part section of the rear end of an outboard motor boat having thereon a safety device constructed according to another embodiment of this invention.

Referring now to the drawings by numerals of reference, and first to FIGS. 1 4, 10 denotes generally an outdrive motor boat having a bottom 11 and a transom 12. Mounted within the boat on a supporting structure not shown is a motor 14. The motor has a rearwardly extending output shaft 15 supported by axially spaced bearings 16 within the neck 18 of a support 19. Support 19 extends Ithrough an opening 20 in transom 12 and is securely connected to the transom by bolts 21.

Output shaft 15 of motor 14- is adapted to supply power to a propeller structure 25 comprising a housing 26 `which extends generally vertically relative to the boat when the structure is in normal operating position, FIG. l. Housing 26 has a lower portion 2S which normally projects below the bottom 11 of boat 10 and supports a fore and aft extending shaft 29 by means of axially spaced bearings 30. Shaft 29 projects forwardly of the housing and has a propeller 31 suitably fastened to it.

Shaft 29 has a bevel gear 32 keyed to it which meshes with a bevel gear 34 on the lower end of a vertically extended shaft 35. Shaft 35 is prevented from shifting axially in housing 26 by suitable conventional bearing means 36.

The upper end of the shaft 35 has a bevel gear 38 which meshes with a bevel gear 39 keyed to a fore and aft shaft 40 supported on bearings 41 in an upper portion 42 of housing 26. Shaft 40 has a forwardly projecting splined outer end 44. The outer end of the output shaftl 15 of motor 14 is splined at 45. These respective splined shaft portions are inter-connected by a conventional close coupled double universal 46. Thus, the power output of motor 14 is transmitted through the universal 46 to bevel gear 39. Bevel gear 39 drives the bevel gear 3S and from there through the shaft 35 to the bevel gear 34. Gear 34 drives bevel gear 32 which in turn drives the shaft 29 on which the propeller 31 is mounted. The pitch and normal direction of rotation of the blades of the propeller is such that a propelling force is exerted in a forward direction, as indicated by the arrow 48.

Propeller structure 2S is supported for pivotable swinging movement relative to the transom 12 by means of a Y-shaped member 50 having a lower leg 51 and upwardly extending diverging arms 52 (FIG. 2) and 54 (FIG. l). The upper ends of the arms lare pivotally supported on rearwardly projecting ears 55 of the support 19 whereby the propeller structure may swing from the position shown in FIG. l to the position shown in FIG. 2 about the transverse pivotal axis 56.

Since the mass of propeller structure 25 lis substantially rearwardly of the transom 12 of the boat, the force of gravity tends to pivot the structure in a clockwise direction (FIG. 1) about pivot axis 56. To resist such pivoting and to hold the structure in proper operating position, a stop pin 60 is provided on the boat for engagement with a stop block 61 on the propeller structure. The stop pin 60 extends transversely relative to the boat. It is supported on and extends between a pair of bracket members 62 extending rearwardly from the transom 12 and connected to the transom by the bolts 64. The bracket members 62 have a plurality of holes 65 whereby the stop pin can be set in desired position to establish the normal operative position of the propeller structure 25. The stop block 61 is provided on the lower end of leg 51 of Y-shaped member 50. Suitable bearings 66 and bracket structure 68 is provided for connecting the propeller structure to the support 50.

In order to detachably connect structure 25 to the stop pin 60, a releasable latch 69 is provided. The latch 69 will hold the propeller structure against rearward swinging unless a force is directed against the latch suiiicient to release it.

Since pivot axis 56 is transverse to the direction of travel of the boat and to the output shaft of the motor 14, when propeller structure engages an obstruction such as a sand bar or floating board, it will swing rearwardly from the position shown in FIG. l to the position shown in FIG. 2. When in the position of FIG. l, the lower portion 28 projects below the bottom 11 `of the boat and into the water. However, when the structure is in the rearward position of FIG. 2, the propeller structure is above the bottom of the boat and thus protected.

The structure thus far recited is conventional and is described to establish the environment of the claimed improvement.

When the propeller structure has pivoted rearwardly to the position shown in FIG. 2, the thrust of propeller 31 tends to pivot the structure clockwise and back toward normal position. Further, the weight of the structure tends to pivot it downwardly about the pivot axis 56. The resistance of the water and the structural strength in the components shown are adequate to support a return of the propeller structure under its -own weight. However, return yunder power might cause damage. Therefore, to eliminate the power return of the propeller structure, a safety device 70 is provided for reducing or cutting the power output of the motor 14 when a swing back occurs. Such structure comprises a fore and aft push-pull rod 71 having a forward end 72 connected to motor control means 74, namely a throttle. There is a lever 75 on the throttle to which the push-pull rod 71 is connected. When the lever 75 is in the position shown in FIGS. 1 and 3, power is supplied to propeller 31. However, when lever 75 is pivoted in a counter clockwise direction to the position of FIG. 4 the motor is throttled down to an idle position.

The rearward end 76 of the push-pull rod 71 extends through the transom 12 and is connected to one leg of a bell crank 78. The bell crank is pivotally supported on a bracket 79 connected to the backside of the transom 12. Bracket 79 has a guide sleeve 80 in which a rod 81 is vertically reciprocal, the lower end of the rod having a cam follower 82 in operative engagement with a cam 84. `Cam 84 is connected to Y-shaped member 50 whereby when propeller structure 25 swings rearwardly relative to the boat, cam 84 pivots about the axis 56 causing the rod 81 to be shifted upwardly. Movement of rod 81 upwardly 4 operates through bell crank 7S to shift the push-pull rod 71 forwardly to thereby operate control means 74.

4Cam 84 has a sharp step 85 shown best in FIG. 4. The step is so located relative to the follower 82 on the rod 81 that the first initial movement of the propeller structure rearwardly of the transom 12 produces a shifting of rod 71 and thereby immediately cuts the power output of the motor 14. The action which occurs can be seen by comparing the diagrammatic views in FIGS. 3 and 4.

Cnce push-pull rod 71 has been actuated, it is held in a forwardly disposed position by the arcuate surface 86 of the ca m 84. When the propeller structure swings back to normal position after the obstruction has been cleared, the cam follower continues to keep engagement with the cam surface 86 for the major portion of its return swing. It is only at the last segment of the return that the follower 82 is free to resume its position as shown in FIG. l. However, it will not return until the boat yoperator manually shifts rod 71 rearwardly. The rubber sleeve 77 in transom 12 through which rod 71 extends serves to guide the rod and also exert a mild frictional hold on it. 'Therefore, the power output to propeller 31 may not be resumed until the propeller structure is substantially back to normal position, and then only upon positive action of the boat operator. i Since the structure provided is such that when the pushpull rod 71 is shifted forwardly by the action of the ca m 84 it remains in such position to hold the motor idle until the rod is manually reset. The speed of the boat will never be cut off and then rapidly cut in again. Such a stop and go action might injure the boat operator.

The embodiment of the invention shown in FIGS. l-4 relates to a throttle control of the motor 14. FIG. 5 shows a mot-or shut-off switch responsive to a rearward pivoting of the propeller structure. The device is shown with the switch opened. The cam 84 is shown swung about the axis 56 to thereby operate rod 81 slidable `in sleeve S0 of bracket 79. Rod 81 pivots a bell crank member 90 having a lost-motion connection therewith at 91. A reciprocal rod 94 is provided and connected at one end to the bell crank 90 and at its opposite end Vto a pivoted member 95 which carries a contact 96 cooperative with a contact 98 to control the circuit to the motor 14. An over center spring 92 holds the rod 94 in the position shown after the circuit has been broken, thereby requiring that the structure be manually reset after a break away ofthe propeller structure has occured so that the operator can control the restarting of the motor.

Referring to FIG. 6, there is shown another embodiment of the invention. Speciiically, the safety device is shown applied to an outboard motor boat. The outboard motor is generally designated 100. It has a lower propeller portion 101 which projects below the bottom 11 of the boat and includes a propeller 102. The outboard motor is mounted on the transom 12 by means of a C-shaped member 104 and a threaded clamp member 105. A pivotal connection 106 is provided between portions of member 104 whereby the outboard motor may pivot and swing rearwardly relative to the boat if the lower portion 101 engages an obstruction.

Connected to the iixed portion of member 104 is a cam 108. The cam 108 is a stationary cam and when the outboard motor pivots it moves relative to it. The head 109 `of the motor has -a control box 110 mounted thereon which includes a switch 111 for opening and closing the circuit to the motor. One of the contacts of the switch is carried on a rod 112 having a cam follower 114 at its lower end and biased downwardly by a spring 115. Therefore, if the outboard motor pivots counter-clockwise from the position shown in FIG. 6, follower 114 is freed from cam 108 whereupon spring 1,15 is able to push the rod 112 downwardly and break the circuit to the motor.

`While the embodiments of the invention relate to reducing power output of motors of boats by means of throttle control or a shut-off switch, it will be apparent that other means could be employed such as slip clutches or the like. The particular power reduction means employed is not critical, any means being suitable so long as the power output of the motor is reduced when the propeller structure swings back on engaging an obstructlon.

With the structure described, if the boat encounters an obstruction as it moves through the water the propeller structure will break away to protect it from damage and immediately the power output of the motor will be cut. Thus, when the obstruction is passed the motor thrust will be eliminated as a factor in returning the propeller structure to its normal position. Where a throttle is employed, the motor will be throttled down on the rearward swing of the motor and stay in a throttled down position until it is manually reset by the boat operator. This also provides a further safety feature. However, if desired, it will be apparent that spring means or the like could be provided to return throttle control lever back to its original position when the propeller structure swings back.

`While this invention has been described in connection with several embodiments thereof, it will be understood that it is capable of further modifications and this application is intended to cover any variations, uses or adaptations of the invention following, in general, the principles of the invention and including such departures from the present disclosure as come within known or customary practice in the art to which the invention pertains and as fall within the scope of the invention or the limits of the intended claim.

Having thus described my invention, what I claim is:

A safety device for a boat adapted to travel forwardly and having, in combination, a rear transom, a propeller structure mounted on said transom for pivotal movement about a horizontal axis transverse to said travel from a rst position wherein it projects below the bottom of the boat to a second position wherein it is elevated above the boat bottom, a cam on said propeller structure and pivotal therewith, a motor supported on said boat, drive means connecting said motor to said propeller structure regardless of the position of such structure, means on said motor for regulating the power output thereof, a push-pull rod extending fore-and-aft relative to said boat and having a forward end connected to said motor regulating means and a rear end extending through said transom, a bell crank mounted on said transom for pivotal movement about an axis parallel to said transverse axis, said bell crank having rst and second legs, said first leg being connected to said rod rear end, lost-motion means connecting said second leg to said cam, said cam causing said bell crank to be pivoted and said rod pushed forwardly when said propeller structure is pivoted, and means on said transom yieldably holding said rod against rearward movement after it has been pushed forward thereby requiring a manual reset.

References Cited in the le of this patent UNITED STATES PATENTS 1,824,213 Johnson Sept. 22, 1931 2,706,959 Downs Apr. 26, 1955 2,752,875 Hills `luly 3, 1956 2,946,306 Leipert July 26, 1960 

